Objective:To establish an environmental management strategy for the prevention of ventilator-associated pneumonia from the perspective of etiological characteristics and to verify its application effect.Methods:Based on a sampling survey, this study constructed preventive management strategies for ventilator-associated pneumonia by blocking pathogen characteristics from the perspective of both colonization and infection management in patients. From July 2021 to June 2023, a non-synchronous randomized controlled study was conducted, including a control group of 59 cases and an experimental group of 57 cases from ICU of Tianjin Teda Hospital, all of them were mechanically ventilated patients. The effectiveness of the strategy was confirmed.Results:In the control group, there were 35 males and 24 females, with an average age of (46.97 ± 18.84) years. In the experimental group, there were 39 males and 18 females, with an average age of (47.49 ± 13.85) years. During the study period, there were 9 cases of ventilator-associated pneumonia (VAP) in the control group and 2 cases in the experimental group, the difference between the two groups was statistically significant (exact odds ratio=0.031). The duration of mechanical ventilation in the experimental group (122.41 ± 18.36) h, which was shorter than that in the control group (187.62 ± 18.05) h, and the difference was statistically significant ( t=19.28, P<0.05). The length of ICU stay in the experimental group was (8.38 ± 0.79) d, in the control group was (10.99 ± 1.10) d, the difference between them was statistically significant ( t=14.66, P<0.05). On the 7th day, there were 7 cases of positive pathogenic bacteria in sputum culture in the experimental group, which was significantly different from the 29 cases in the control group ( χ2=16.73, P<0.05). Conclusions:The vector management strategy for preventing ventilator-associated pneumonia by blocking etiological characteristics can reduce the incidence of VAP, shorten the duration of mechanical ventilation and ICU stay, and reduce the pathogen load in the sputum of mechanically ventilated patients on the 7th day.

OBJECTIVE To study the protective effect and possible mechanism of soybean isoflavones against threatened miscarriage rats. METHODS Female mice were selected to promote estrus and mate with male mice. After pregnancy， they were randomly divided into normal group （purified water， i.g.， n＝10）， model group （purified water， i.g.， n＝9）， positive control drug group （progesterone 4 mg/kg， i.m.， n＝9）， low-， medium- and high-dose soybean isoflavone groups （25， 50 and 100 mg/kg， i.g.， n＝10）. Except for the normal group， the rest were given mifepristone+misoprostol on the 8th day of pregnancy to establish threatened miscarriage model， and then given purified water or drugs， once a day， on days 1-7 and 9-12 of pregnancy， respectively. At 14 days of pregnancy， the rates of fetal protection were counted. Serum levels of β-human chorionic gonadotrophin （β-HCG） and progesterone （P） in rats were detected. Pathological and morphological changes in rat placenta and decidua tissues were observed， and the apoptosis indexes of cells were detected； mRNA and protein expressions of factor of apoptosis related （Fas）， factor of apoptosis related ligand （FasL）， proliferating cell nuclear antigen （PCNA） and heparin binding epidermal growth factor （HB-EGF） were determined in placenta tissues， and mRNA and protein expressions of Fas， PCNA and HB-EGF in decidua tissues were detected. RESULTS In the model group， the placental tissues of rats were hyperemia and dilatation， with fewer and irregular blood vessels； severe stromal edema，inflammatory cell infiltration and iron-choledrin depositionwere observed. Compared with model group， the fetal survival rates， serum levels of β-HCG and P， the expressions of PCNA and HB-EGF mRNA and proteins in the placenta and decidua tissue of soybean isoflavone groups increased significantly （P＜ 0.05）， while pathological changes were improved significantly； cell apoptosis index in the placenta and decidua tissue， the expressions of Fas， FasL mRNA and proteins in the placenta and Fas mRNA and protein in the decidua tissue decreased significantly （P＜0.05）. The effect of soybean isoflavones was dose-dependent （P＜0.05）. CONCLUSIONS Soybean isoflavone has protective effect on threatened miscarriage， the mechanism of which is related to down-regulating the expressions of Fas and FasL mRNA and protein at the maternal-fetal interface， and up-regulating the expressions of mRNA and protein of PCNA and HB- EGF.

Objective:To analyze the epidemiological characteristics and pathogen spectrum of influenza outbreaks in Shaanxi Province from 2014 to 2023 and provide basis reference for strengthening regional influenza prevention and control.Methods:The data were collected from the Public Health Emergency Management Information System of the China Disease Prevention and Control Information System and the China Influenza Surveillance Information System. On-site epidemiological investigation information and etiological test results of influenza network laboratories reported in Shaanxi Province during 2014-2023 were collected, and descriptive analysis was conducted on the time, region, and location distribution of influenza outbreaks. SPSS 25.0 software was used for statistical analysis.Results:A total of 386 influenza outbreaks were reported in Shaanxi from 2014 to 2023, with a total attack rate of 1.81% (14 880/821 001). The epidemic peaks mainly occurred in winter and spring (November to March of the following year), and there was an alternating pattern of epidemic peaks in different years (the early peak was in December, and the late peak was in March of the following year). The epidemic areas were mainly concentrated in the Qinba Mountains of southern Shaanxi (209, 54.15%) and Guanzhong Plain (173, 44.82%). The epidemic places were mainly distributed in primary schools (239, 61.92%), and the differences of epidemic areas and places were statistically significant (all P<0.001). Influenza A(H3N2) viruses were the predominant pathogen in the outbreak (849, 57.76%), and influenza A(H3N2), B (Victoria) lineage and A(H1N1)pdm09 virus alternately dominated the epidemic peak in different years. Conclusions:The peak of influenza outbreaks in Shaanxi Province was winter and spring during 2014-2023. Primary schools in the Qinba Mountains of southern Shaanxi and Guanzhong Plain should be targeted for prevention and control. In the prevention and control programs, close attention should be paid to the changing trend of dominant strains. Effective intervention measures should be targeted to the high-incidence areas and seasons.

Objective: To monitor the prevelance of Neisseria meningitidis among healthy children and adolescents aged 3-18 in Anhui Province, so as to provide support for epidemic cerebrospinal meningitis prevention and control. Methods: From September to October in 2021 and 2022, 4 033 healthy children and adolescents aged 3-18 were selected by stratified random sampling from Anhui Province, including areas north of the Yangtze River (Bozhou, Fuyang, Bengbu, Huainan, Chuzhou, Hefei) and areas south of the Yangtze River (Wuhu, Maanshan, Tongling, Anqing, Chizhou, Xuancheng) and the secretions of children and adolescents were collected from the posterior pharyngeal wall above the uvula, and the strains were identified by bacterial culture and nucleic acid detection. McNemar test and Kappa consistency test were used for statistical analysis. Chisquare test and Chisquare trend test were used to compare the rates. Results: The carrier rates of Neisseria meningitidis were 0.47% and 1.07%, respectively. The sensitivity of nucleic acid detection was higher. Among the detected bacteria, group B accounted for the largest proportion of 76.74%. It was followed by group C (4.65%), group Y (4.65%), group W 135 (2.33%) and group X (2.33%). The bacteria bearing rate of male students was higher than that of female students (χ2=11.44); with the increase of age, the bacteria bearing rate of children and adolescents showed an increasing trend (χ2trend=42.69); the bacterial bearing rate of children and adolescents in the north of the Yangtze River was higher than that in the south of the Yangtze River (χ2=23.19); the bacteria bearing rate of children and adolescents without immune history was higher than that with immune history (χ2=11.02)(P<0.01). Conclusions Neisseria meningitidis group B has become an epidemic strain in Anhui Province, and senior children and adolescents have become the key population of epidemic prevention and control. It is necessary to continue to do a good job in the surveillance of epidemic cerebrospinal meningitis disease and focuse on group B disease cases, so as to prevent the occurrence of cluster outbreaks in schools.

Objective:To validate the feasibility of the gamma analysis method in the study of prescription dose conversion between logistic nanodosimetry model (LNDM) and microdosimetric kinetic model (MKM) basing on the Chinese self-developed model LNDM by applying clinical experiences of National Institute of Radiological Science (NIRS).Methods:Physical dose distributions derived from the MKM- and LNDM-based carbon ion treatment plans were compared via the method of gamma analysis under the open-source treatment planning platform matRad. In this way, the prescribed dose conversion factor between the MKM- and LNDM-based treatment plans was obtained. Using water phantoms, the influence of geometric shape, size, depth of target volume (TV), prescribed dose and field setting on the conversion factor was investigated comprehensively. Moreover, preliminary verification of the acquired conversion factor was conducted on the C-shape model and a case of liver cancer patient.Results:The conversion factor depended on the field setting rather than the TV shape. Under the condition of single field, the conversion factor was positively correlated with the size and depth of TV, and the prescribed dose. Moreover, the conversion factor was successfully verified using the C-shape model and the patient with liver cancer, where the gamma passing rates (2%/2 mm) of the physical dose distribution generated by the MKM and LNDM treatment plans were 92.79% and 91.19%, respectively.Conclusions:The conversion factors (f=D LNDM/D MKM) obtained in this study might provide guidance for the prescribed dose setting during the carbon ion treatment planning based on the LNDM. Besides, the gamma analysis method could be used for the study of the prescribed dose conversion between different models.

Mycoplasma pneumoniae pneumonia (MPP) complicated with cerebral venous sinus thrombosis (CVST) is rare.We retrospectively analyzed the clinical data of two patients with refractory mycoplasma pneumoniae pneumonia (RMPP) complicated with CVST who were hospitalized in Xi′an children′s Hospital from December 2018 to April 2019, inquired the relevant literature, analyzed the clinical diagnosis and treatment characteristics, and discussed the diagnosis and treatment measures of RMPP complicated with CVST.Two cases were 6-year-old girls with fever and cough as the main symptoms.After physical examination, the respiratory sounds of the affected lung decreased, and the sounds of phlegm and dampness could be heard in both lungs.Mycoplasma pneumoniae (MP) antibody and RNA were positive.Chest CT showed lobar pneumonia with a large number of pleural effusion.The effect of macrolide antibiotics anti infection treatment was not good.Headache symptoms occurred during the course of the disease, and serum D-dimer increased significantly.Brain MRI showed CVST, including 1 case with lower extremity pain, and B-ultrasound showed right lower extremity arterial embolism.After anti infection, thrombectomy, anticoagulation and symptomatic treatment, 2 cases were discharged.When children with MPP, especially those with RMPP, have extracranial thrombosis and/or neurological symptoms, accompanied by elevated serum D-dimer, the possibility of CVST should be considered, and brain MRI examination should be performed in time to confirm and actively treat, which can reduce or avoid the occurrence of sequelae.Thrombosis may be related to excessive inflammatory reaction and vascular endothelial injury caused by MP infection.

Objective To evaluate the change of serum creatinine (Scr) before and after administration of contrast agent in different dose,to observe the difference of dog's kidney tissue with electron microscopy and investigate the effect of contrast agent on renal function.Methods Twelve dogs were divided into four groups randomly:the control group,the low dose group,the moderate dose group and high dose group.After the administration of different doses of iodine contrast agent at the same rate,the changes of Scr and microscopic structure were compared before administration and 48 hours later.Results The differences of Scr before and 48 hours after administration were (4.6±1.6) μmol/L,(6.7±2.5) μmol/L,(6.9±4.5) μmol/L,(5.1± 1.9) μmol/L for control group,low dose group,moderate dose group and high dose group,respectively.There was no statistically significant difference among the groups (P ＞0.05).In high dose group,the mitochondria of tubular epithelial cells were swelling and obvious vacuoles were observed.Only a small amount of vacuoles existed in the renal tubular epithelial cells in low dose group.Conclusion Compared with the moderate and high dose group,the low-dose iodine contrast agent have less damage to the kidney cells of the dogs.

Objective To study the feasibility and value of magnetic resonance diffusion tensor imaging (DTI) to monitor non?arteritic anterior ischemic optic neuropathy (NAION). Methods Thirty eight NAION patients (56 eyes) were divided into acute period in 17 eyes, progressive period in 16 eyes and chronic period in 23 eyes at the base of onset time. According to matching principle, 56 eyes in 38 normal controls (NCs) were enrolled. All the patients and NCs underwent MR and DTI scan. The raw data were processed by two experienced radiologists, mean diffusivity (MD), axial diffusivities (λ//), radial diffusivities (λ┴), fractional anisotropy (FA) and Length value were got. The independent sample t test was used for the parameter values between the NAION group and the NCs group. A single factor variance analysis was used to compare the parameters among different stages of NAION group. Results Compared to the NCs group, the values of FA and Length in NAION group were reduced [0.20±0.11 vs 0.31±0.12, (5.85±0.92) vs (65.11± 6.89) mm], and the differences were statistically significant (t=-4.28,-5.25;P<0.05). The values of MD andλ┴were increased [(0.16±0.04)×10-3 vs (0.10±0.04)×10-3 mm2/s, (0.16±0.05)×10-3 vs (0.09±0.03)×10-3 mm2/s] in NAION group and the differences were statistically significant (t=6.83, 7.10;P<0.05). The value of FA and Length in acute period, progressive period and chronic period of the NAION group decreased differently compared to the NCs group. At the same time, the value of MD value and λ┴in the three periods of the NAION group increased compared to the NCs groupand the differences were statistically significant (P<0.05). The value of FA between the acute period, the progressive period, and the chronic period of NAION group were statistically signficant (F=10.88, P<0.05). However, no significant differences were found in the values of MD, λ┴and Length of the NAION group (F=0.23, 0.64, 0.33, 1.38;P=0.79, 0.54, 0.72, 0.27). Conclusion The parameters of DTI can be used to monitor the damage of optic nerve and development in NAION.

Objective: To investigate the osteointegration and osteoinduction of nano hydroxyapatite/bioglass ( nHA/BG ) gradient nanofilm on the surface of titanium ( Ti) prepared by hypotherm sintering and plastic deformation. Methods:Hypotherm sintering was used to produce nHA/BG gradient coating followed by soaking in the simulated body fluid. Ti implants with gradient coatings were planted in femoral condyles at one side of 12 New Zealand rabbits and the untreated Ti implants were planted at the other side as the controls. 1, 3 and 6 months after implantation, the animals were sacrificed after X-ray examination and the tissues around the implants from the 3 month group were used for the preparation of hard tissue section and ground section. New bone formation was observed by tetracycline fluorescence staining. Von Gieson staining was used to observe the osteointegration at the interface between bone and im-plant. Results:The gradient coatings were porous and composed of irregular rod-like nano-HA crystals. Animal study showed well es-tablished osteointegration between the gradient coating and more novel bone was found around the implants with gradient coatings. Conclusion:Osteointegration and ostioinduction of Ti implant can be enhanced by nanostructured surface with gradient coatings of nHA/BG.

Objective To analyze the massive explosions and burn at Tianjin Port in 2015 resulted in a mass casualty event,and the entire course of response of a hospital to deal with such major sudden accident in order to find a rational strategy for optimal use of medical resources and reduce the critical mortality.Methods This study was done by a retrospective analysis of data from one trauma center at an academic hospital.Data including outcome,triage,severity and pattern of injuries,patient flow,and medical resources used were obtained by the review of hospital records.Results This disaster caused 165 deaths,8 missing contact,and 797 non-fatal casualties.The Pingjin Hospital admitted 298 casualties,and 29 of them were seriously injured referred to by Tianjin Emergency Medical Center.Excessive triage rate made after transfer to another hospital was 62.07% with 11 of the 29 severely injured patients.Maximum (also the first)surge had 147 injured patients arrived around one hour after incident,the second surge had 31 seriously injured patients occurred around 4 hours after incident.Of them,17 patients needed surgery and 17 patients were admitted to the intensive care unit.Conclusions These data showed that the number of casualties in the first surge was substantially larger than predicted and those casualties had less severe trauma,whereas the number of the injured in the second surge was less but the trauma was more severe.In order to maintain the hospital surge capacity,an effective re-triage and a hospital-wide damage control principle can be used to deal with.